Cam grinding machine



1953 c. J. GREEN 2,660,838

CAM GRINDING MACHINE Filed Dec. 17, 1950 6 Sheets-Sheet 1 CLARE/v5: =J.GREEN By ATT'or-ney I9 70 a 77 I w {I I5 i4 8/ a 79 l nven o 1953 c. J.GREEN 2,660,838

CAM GRINDING MACHINE Filed Dec. 17, 1950 6 Sheets-Sheet 2 I] Inverfl'brCLARENCE :J. GREEN By A Tfor-ne Dec. 1, 1953 c. J. GREEN CAM GRINDINGMACHINE 6 Sheets-Sheet 3 Inver/Tor A RENEE IL/- GREEN By 'Afforney FiledDec.

Dec. 1, 1953 c. J. GREEN 2,660,838

CAM GRINDING MACHINE Filed Dec. 17, 1950 e Sheets-Sheet 6 764 v 27 V v774 277 17a FIG '1 7 1 78 I-n\/ enTor CLARENCE 1-J. GREE Patented Dec.1, 1953 UNITED STATES PATENT OFFICE CAM GRINDING MACHINE Clarence J.Green, Worcester, Mass, assignor to Norton Company, Worcester, Mass., acorporation of Massachusetts Application November 17, 1950, Serial No.196,263

13 Claims. 1

The invention relates to grinding machines, and more particularly to anautomatic cam grinding machine for grinding a plurality of spacedintegral cams on a camshaft to predetermined contours and tapers.

One object of the invention is to provide a simple and thoroughlypractical automatic cam grinding machine to grind a plurality of camswhich taper in opposite directions. Another ob ject of the invention isto provide a grinding machine having a rotatable work: support on alongitudinally movable swivel table with an automatically actuatedmechanism for swivelling the table in opposite directions to facilitategrinding opposite tapers on spaced portions of a workpiece. Anotherobject is to provide a cam grinding machine having a longitudinallymovable swivel table with a swivelling mechanism which is actuatedautomatically by and in timed relation with the longitudinal movement ofthe table successively to swivel the swivel table in opposite directionsto grind oppositely tapering surfaces on certain of the cams beingground.

A further object of the invention is to provide a suitable wheel feedingmechanism having a table actuated stop mechanism for limiting theinfeeding movement of the grinding wheel to compensate for theswivelling movement of the table. Another object of the invention is toprovide a master cam assembly with stepped master cams which arearranged to compensate for the swivelling of the swivel in grindingoppositely tapering surfaces on spaced cams on a camshaft.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described and the scopeof the application of which willbe indicated in the following claims.

In the accompanying drawings in which is shown one of various possibleembodiments of the mechanical features of the invention,

Fig. 1 is a front elevation of a grinding machine.

mately on the line 44! of Fig. 3, through the wheel slide and wheelslide base;

Fig. 5 is a fragmentary sectional view, on an enlarged scale, takenapproximately on the line 55 of Fig. 4, showing the fluid motor forrapidly positioning the wheel slide;

Fig. 6 is a fragmentary vertical sectional view, on an enlarged scale,taken approximately on the line 66 of Fig. 3, showing the star wheel anddog indexing mechanism;

Fig. '7 is a fragmentary plan view, on an enlarged scale, of thehydraulically operated mecha-' nism for swivelling the worktable;

Fig. 8 is a fragmentary front elevation, taken approximately on the line8-8 of Fig. 7;

Fig. 9 is a fragmentary sectional detail view, on an enlarged scale,taken approximately on the line 9--9 of Fig. 7;

Fig. 10 is a fragmentary sectional detail view, on an enlarged scale,taken approximately on the line ill-10 of Fig.7;

Fig. 11 is a fragmentary detail view, on an enlarged scale, takenapproximately on the line H- l I of Fig. 7;

Fig. 12 is a fragmentary rear elevation, on an enlarged scale, of therotary feed stop disc for positioning the wheel slide;

Fig. 13 is a fragmentary plan view, on an mechanism;

Fig. 14 is a diagrammatic view showing the worktable swivelled in acounter-clockwise direction for grinding cams I, 2, 5 and 6 with facestapering toward the right;

Fig. 15 is a similar diagrammatic view showing the worktable swivelledin a clockwise direction for grinding cams 3, 4, I and 8 with facestapering toward the left;

Fig. 16 is a combined hydraulic and electrical diagram of the operatingmechanisms and the controls therefor;

Fig. 1'7 is a hydraulic diagram of the wheel feeding mechanism;

Fig. 18 is a diagrammatic view of a modified construction, showing theswivel table swivelled in a counter-clockwise direction in which steppedmaster cams are utilized; and

Fig. 19 is a similar diagrammatic view showing the swivel tableswivelled in a clockwise direction.

An automatic cam grinding machine has been illustrated in the drawingscomprising a base l0 which supports a longitudinally movable -work-.

table H on the usual fiatway l2 and V-way l3 formed on the upper surfaceof the base I 0. The longitudinally movable table I I supports a swiveltable [4 which is arranged to pivot on a stud l5.

The base It also supports a transversely movable wheel slide l6 which isarranged to slide transversely on a V-way l1 and a flat/Way l8 formed onthe upper surface of a transversely movable wheel slide base I9. Thewheel slide base I9 is in turn supported on a V-way '28 and a fiatway 2|formed on the upper surface of the base Ill. The wheel slide I6 isprovided with a rotatable wheel spindle 22 journalled in bearings (notshown). The wheel spindle 22 supports a rotatable grinding wheel 23'. Asuitable driving mechanism is provided for driving the wheel spindle 22and the grinding wheel 23 comprising an electric motor 24 adjustablymounted on the upper surface of the wheel slide 16. The motor 24 isconnected by a V-belt drive (not shown) contained within a belt guard 25(Figs. 1 and 2).

The swivel table 14 serves as a support for a pivotally mounted rock barwhich is pivotally supported by a plurality of spaced bearing brackets3| and 32 which are in turn fixedly mounted on the upper surface of theswivel table I4. The rock bar 30 serves as a support for a master camspindle 33 which extends within a headstock housing 29. The master camspindle 33 is provided with a camshaft supporting center 34 forsupporting the left-hand end of a camshaft 35 to be ground. The rock bar30 also supports a footstock 36 having a footstock center 31 forsupporting the right-hand end of the camshaft 35.

The master cam spindle 33 may be driven by an electric motor 38 (Figs. 1and 2) mounted on the upper surface of the headstock housing 29. Themotor 38 is drivingly connected in a manner (not shown) positively torotate the master cam spindle 33 and the camshaft 35 to be ground. Themaster cam spindle 33 is provided with a plurality of master cams 39which are arranged to be successively engaged by a master cam followerroller 40, which is slidably supported on a rotatable shaft 4|, forcontrolling the rocking movement of the rock bar 30 so as to generatepredetermined contours on the cams being ground. This mechanism is notconsidered to be a part of the present invention and therefore has notbeen illustrated in detail. The drive for the master cam spindle 33 andthe arrangement of the master cams 39 and the follower roller 49 may besubstantially the same as that shown in the prior U. S. Patent No.2,185,837, to G. Crompton, Jr., dated January 2, 1940, to whichreferences may be had for details of disclosure not contained herein.

A suitable mechanism is provided for rapidly moving the wheel slide 66relative to the wheel slide base [9 to cause a rapid approachingmovement of the grinding wheel 23 to and from an operative positionrelative to the camshaft 35 to be ground. This mechanism may comprise afluid pressure cylinder which is fixedly mounted on the wheel slide basel9. The cylinder 45 contains a slidably mounted piston 46 which isconnected to one end of a piston rod 41. The other end of the piston rod4'! is connected to a de' pending bracket 48 which is fixedly mounted onthe underside of the wheel slide [6.

Due to the swivelling of the swivel table I 4 for grinding tapered cams,to be hereinafter described, a suitable stop mechanism is provided tolimit the forward approaching movement of the wheel slide Hi. Thismechanism may comprise a rotatable shaft 50 (Fig. 3) which is journalledin a pair of spaced bearings 5! and 52 in the wheel slide base I9. Aplate 53 is fixedly keyed on the right-hand end of the shaft 50. Theplate 53 is provided with a plurality of spaced adjustable stop studs 54which are arranged to be indexed into an operative position in the pathvof a bracket 55 which is fastened to the right-hand 4 end of the wheelslide l6 (Fig. 3). A shaft 55 is journalled in a bearing 51 which isfixedly mounted within the wheel slide base IS. The shaft 55 is slidablykeyed within a central aperture formed within the left-hand end of theshaft 50. A gear 58 is mounted on the left-hand end of the shaft 56 andmeshes with a gear 59 mounted on a rotatable shaft 60. The shaft 60 isjournalled in a bearing 6! which is fixedly mounted relative to the baseIll. The shaft 60 is also provided with a star wheel 62 (Figs. 3 and 6)which is arranged in the path of a plurality of adjustably spaced dogs63. The dogs 63 are adjustably mounted on the rear surface of theworktable II. A T-slot B4 is formed in the rear edge of the table H tofacilitate supporting and adjusting the dogs 63. The mechanism justdescribed is provided to regulate the extent of a rapid approachingmovement of the wheel slide 16 when the swivel table 14 is swivelled fortaper cam grinding. The stops 54 are numbered 1 to 8 inclusive tocorrespend with the cams l to B on the camshaft 35.

In order to obtain a predetermined controlled feeding movement of thegrinding wheel 23, a suitable feeding mechanism is provided comprising arotatable feed screw 10 which is journalled in bearings H and I2 fixedlymounted relative to the base [0. A depending half-nut T3 depends fromthe under side of tne wheel slide base I9 and meshes with or engages thefeed screw 10. A suitable mechanism is provided comprising manuallyoperable feed wheel 19 for manually rotating the feed screw 10. The feedwheel 79 is mounted on the front of the machine base. A micrometer feedadjusting mechanism an is provided of the well known type, such as forexample that shown in the expired U. S. patent to C. H. Norton, No.762,838, dated June 14, 1904, to which reference may be had for detailsof disclosure not contained herein. This micrometer feed adjustingmechanism 80 serves to facilitate precisely adjusting a stop abutmentnot shown relative to a pivotally mounted stop pawl 81 which ispivotally supported on the front of the machine base I0.

A suitable power operated mechanism is provided for automaticallyrotating the feed screw 10 to impart a feeding movement to the grindingwheel 23. This mechanism may comprise a hydraulic cylinder 16 (Fig. 1'7)which contains a slidably mounted piston 11. A rack bar 18 is formed onthe upper surface of the piston 11 and meshes with a gear 15 mounted onthe end of the shaft 14. The gear 15 meshes with a gear (not shown)mounted on the forward end of a shaft 14a (Fig. 3). This feedingmechanism is substantially identical with that shown in the prior UnitedStates Patent No. 2,522,485 to Herbert A. Silven et al., dated September12, 1950, to whichreference may be had for details of disclosure notcontained herein. It will be readily apparent from the foregoingdisclosure that movement of the piston 11 caused by fluid admitted tothe cylinder 16 will impart a rotary motion to the gear 15 and throughthe shaft 14 will transmit a corresponding rotary motion to the shaft14a and the feed screw 10.

In order to operate the machine automatically the table II is preferablymoved longitudinally by a hydraulic mechanism comprising a cylinder 85which contains a slidably mounted piston 86. The piston 86 is connectedtothe left-hand end of a piston rod 81 (Fig. 16). The right-hand end. ofthe piston rod 81 is connected by a, bracket 88 which is fixedly mountedon the under side of the table II. It will be readily apparent that whenfluid under pressure is passed through a pipe 89 into a cylinder chamber90, the piston 86 together with the table II will be moved toward theright. During this movement, fluid within a cylinder chamber 9| mayexhaust through a pipe 92. Similarly when fluid under pressure is advmitted through the pipe 92 into the cylinder chamber 9 I, the piston 86together with the table I I will be moved toward the left.

An automatic control mechanism may be provided for controlling theadmission of fluid to the cylinder 85 for automatically indexing thetable II successively to position cams on the camshaft 35 to be groundinto operative relation with the grinding wheel 23. This mechanism isnot con-. sidered to be a part of the present invention and consequentlyhas not been illustrated in detail. This mechanism may be substantiallyidentical with that shown in the prior U. S. Patent No. 2,185,837, abovereferred to, to Which reference may be had for details of disclosure notcontained herein.

In modern practice in grinding camshafts for the automotive industry, itis desirable to grind cams not only having a predetermined contour butalso tapering from side to side so that when installed in an automotiveengine, the rotation of the cam on the valve tappet will cause a rotarymotion to be imparted to the tappet. In some automotive engine designsit is necessary due to arrangement of the valves and tappets to providecams having peripheral surfaces tapering in opposite directions. In somecases it is desirable to provide a taper toward the left on all cams onthe left-hand end of the camshaft 35 and to provide a taper toward theright on the remainder of the cams on the right-hand end of the camshaft35. As illustrated in the drawings the machine is set up for grindingalternate pairs of cams tapering in the opposite direction. In order toaccomplish this desired result, a hydraulically operated mechanism isprovided for swivelling the swivel table I4 about its pivot stud in aclockwise direction or counterclockwise direction so as to produce thedesired taper on the cam being ground. This mechanism may comprise ahydraulic cylinder 98 which is fixedly mounted on the longitudinallymovable table II. The cylinder 98 contains a slidably mounted piston 99which is connected to one end of a piston rod I00. The other end of thepiston rod I is reduced slightly in diameter and passes through anelongated hole IIlI formed in a, block I02 (Fig. 10). The block I02 ispivotally supported on a stud I03 which is fixedly mounted on a bracketI94 fastened to the left-hand end of the table II (Figs. 7 and 9-). Thepiston rod I09 passes through a clearance hole I05 in the stud I03. Theelongated hole IOI and the clearance hole I05 are provided to facilitatea free swivelling movement of the table I4 when fluid under pressure isadmitted to the cylinder 98.

When fluid under pressure is passed through a pipe I09 into a cylinderchamber I01 (Fig. 7) the piston 99 is moved downwardly to impart acounter-clockwise swivelling movement to the swivel table I4. Duringthis movement fluid within a cylinder chamber I08 may exhaust through apipe I09. A pair of throttle valves I I0 and I I I are providedrespectively in the pipes I09 and I09 to facilitate controlling thespeed of movement of the piston 99 and the swivelling movement of theswivel table I4. Similarly when fluid under pressure is passed throughthe pipe (ill I09 into the cylinder chamber I08, the piston 99 will bemoved upwardly (Fig. 7) thereby swivelling the swivel table I4 in aclockwise direction.

It is desirable to provide precise means for limiting the swivellingmovement of the swivel table I4 in either direction to facilitategrinding predetermined tapers in opposite directions on the cams beingground. The worktable II is provided with a pair of spaced upwardlyprojecting lugs H5 and H6. The lugs H5 and H6 are provided withadjustable stop screws II! and H8 respectively which are arranged in thepath of a stop lug I I9 which is fastened to the left-hand end of theswivel table I4. By manipulation of the stop screws Ill and II 9, theclockwise and counter-clockwise swivelling of the swivel table I4 may beprecisely controlled.

The actual taper produced on the cams being ground is very slight forexample a small frac tion of one degree. This taper has been somewhatexaggerated in the drawings (Figs. 14 and 15) to clarify theillustration. As shown in Fig. 14, the swivel table I4 is swivelled in acounterclockwise direction to illustrate diagrammatically the relativeposition of the camshaft 35 and the grinding wheel 23 while grindingcams I, 2, 5 and 6. Similarly in Fig. 15, the swivel table has beenswivelled in a clockwise direction to show diagrammatically the relativeposition of the camshaft 35 and the grinding wheel 23 while grindingcams 3, 4, I and 8 on the camshaft 35. It will be readily apparent fromthe foregoing disclosure that cams I and 2 are ground while the swiveltable I4 is swivelled in a counterclockwise direction after which thetable is swivelled in a clockwise direction for grinding cams 3 and 4.The swivel table I4 is again swivelled in a counter-clockwise directionto position the camshaft 35 for grinding'cams 5 and 6 after which theswivel table is again swivelled in a clockwise direction to position thecamshaft 35 for grinding cams l and 8 so that alternate pairs of camswill be ground tapering in opposite directions.

It is desirable to provide a wheel spindle reciprocating mechanism forreciprocating the grinding wheel spindle 22 axially within its bearingsduring a grinding operation. This mechanism may comprise a worm I25(Fig. 13) mounted on the wheel spindle 22. The worm I25 meshes with aworm gear I25 mounted on a vertical shaft I27. The vertical shaft I2! isprovided at its upper end with an eccentric stud I28 which supports aneccentric disc I29. The eccentric disc I29 is surrounded by one partof aconnecting rod I30. The connecting rod I30 is provided with a yoked endI3I which engages a stud I 32 carried by a pivotally mounted yokedmember 533. The yoked member I33 is pivotally supported on a stud I34which is fixed relative to the wheel slide I5. A tension spring I35 isconnected between a stud I35 on the yoked member I 33 and a stud I31fixedly mounted within the wheel slide I9. The spring I35 servesnormally to maintain the stud I32 positioned within the yoke I3I. Theyoked member I33 is provided with opposed studs (not shown) which engagea groove (not shown) formed on the wheel spindle 22. It will be readilyapparent from the foregoing disclosure that rotation of the wheelspindle 22 will be imparted through the worm I25, the worm gear I25, theshaft I21, the eccentric stud I28, the eccentric disc I29 to oscillatethe connecting rod I39 which serves to impart an oscillating movement tothe yoked member I33 thereby reciprocating the wheel spindle 22 axiallywithin its bearings. A pipe I55 connects the control valve I60 with acylinder I56. The cylinder I56 contains a slidably mounted piston I51which is arranged automatically to stop and to start wheel spindlereciprocation before and after a grinding wheel truing operation. A pipeI58 connects the control valve I66 with other mechanisms of the machine(not shown).

The mechanism as above described includes a stop plate 53 having aplurality of stop pins or studs 54 for limiting the approaching movementof the grinding wheel 23 so as to compensate for the swivelling movementof the swivel table I4. This compensation may also be obtained asillustrated diagrammatically in the modification shown in Figs. 18 and19. In the latter figures, the diameter of the master cams 39 may bestepped or graduated, that is, of different diameters to compensate forthe swivelling of the swivel table I 4 so that the cams on the camshaft35 to be ground will be ground to the same diameter. In utilizing thismodified construction as diagrammatically illustrated in Figs. 18 and19, the wheel slide I6 is fed into a predetermined forward approachingposition before the wheel 23 is moved into operative engagement to grindeach successive cam on the camshaft 35.

The grinding wheel 23 is formed with a true cylindrical operative face.The wheel may be maintained in true cylindrical form by means of asuitable truing apparatus such as for example, a wheel guard truingmechanism mounted on top of the wheel guard or the wheel slide or atruing tool adjustably fixed on the longitudinally movable worktable II,in which case the truing tool is traversed in a direction parallel tothe grinding wheel axis. With such an arrangement the grinding wheel maybe readily trued regardless of the position of the swivel table. Ifdesired a table type truing apparatus may be provided such as a truingtool I40 which is mounted on the rock bar 30. This truing apparatus maybe substantially the same as that shown in the prior U. S. patent toCrompton above referred to. In utilizing this type of truing mechanism,the swivel table must be swivelled to a central position for the truingoperation. In order to locate the swivel table I4 in position fortruing, a hydraulically operated mechanism may be provided comprising acylinder I45 (Fig. '1) which contains a slidably mounted piston I46. Thepiston I46 is provided with an integral piston rod I41 which carries astop block I48. The stop block I48 is arranged so that it may be movedinto the path of the lug I I6 on the table I I and a stop screw I49carried by the lug II9 on the end of the swivel table. When fluid underpressure is passed through a pipe I58 into a cylinder chamber II, thepiston I46 is moved toward the right (Fig. '1) to move the stop blockI48 into an operative position. During this movement, fluid within acylinder chamber I52 may exhaust through a pipe I53 and through a valveI54. The valve I54 is provided in case it is desired to render thecylinder I45 and the piston I46 inoperative. In the latter case when thepiston I46 is in a left-hand end position (Fig. '1), the cylinderchamber I52 is filled with fluid, the valve I54 may be closed therebylockingthe fluid within the cylinder chamber I52 and holding the pistonI46 and the stop block I48 in an inoperative or left-hand end position.The operation of the cylinder I45 is automatic and ties in with theautomatic control system to be hereinafter described.

A suitable hydraulic control mechanism is provided for controlling theadmission to and exhaust of fluid from the cylinders 98 and I45. Thiscontrol mechanism may comprise a solenoid actuated valve I66 which isactuated by means of a solenoid SI, a control valve I6I which isactuated by a solenoid S4 and a control valve I62 which is actuated bythe solenoids S2 and S3. The control valve I60 serves to control theadmission of fluid to the cylinder chamber I5I in the cylinder I45 formoving the stop block I48 into an operative position. The control valveI62 serves in one position to admit fluid under pres sure to the controlvalve I6I and in the other position to admit fluid through the pipe I69into the cylinder chamber I08 to move the piston 99 upwardly (Figs. 7and 16) to swivel the swivel table I4 in a clockwise direction. Thecontrol valve I6I, in the position illustrated in Fig. 16, serves topass fluid under pressure through the pipe I06 into the cylinder chamberIII! to move the piston 69 downwardly thereby rocking the swivel tableI4 in a counter-clockwise direction into the position illustrated inFig. 16. In the reverse position of the valve I6I, fluid is passedthrough the pipe I53 into the cylinder chamber I52 to move the pistonI46 toward the left (Figs. 7 and 16) to withdraw the stop block I48 toan inoperative position. As above explained if desired the stop blockI48 may be locked in an inoperative position by closing the valve I54when the piston I46 is in a left-hand end position (Figs. 7 and 16).

As shown in Fig. 16 the machine is set up for grinding alternateadjacent pairs of cams on the camshaft 35 tapering in th oppositedirections as shown in Figs. 14 and 15. A pipe I64 serves to supplyfluid under pressure to the solenoid actuated valve I68. The valve I 68comprises a slidably mounted valve member I63 which is normally held ina right-hand end position by means of a compression spring I66. When thesolenoid SI is energized, the valve member I63 is shifted toward theleft. When the solenoid SI is energized, fluid under pressure from thepipe I64 may pass through a valve chamber I65, through the pipe I56 intothe cylinder chamber I5I to move the piston I46 toward the right intothe position illustrated in Fig. '7 thus moving the stop block I48 intoan operative position.

The fluid actuated control valve I6I is a pressure actuated valvecomprising a slidably mounted valve member I68 the movement of which iscontrolled by a pilot valve I69. The pilot valve I69 comprises aslidably mounted valve member I10 which is normally held in a right-handend position by means of a compression spring Ill. The solenoid S4 whenenergized serves to shift the valve member I 68 into a right-hand endposition. In the position as illustrated in Fig. I6, fluid underpressure passing through the pipe I64 passes through a passage I13 intoan end chamber I14 .to move the valve member I68 into an extremeleft-hand end position as shown in Fig. 16. During this movement fluidwithin an end chamber I15 may exhaust through a passage I16, through acentral passage I11 in the pilot valve member I10 and exhaust through apipe I18.

In the position of th valve member I68 (Fig. 16) fluid under pressurepassing through the pipe I86 passes through a valve chamber. I81

9 and through the pipe I86 into the cylinder chamber I81 to cause adownward movement of the piston 99, thereby rocking the swivel table ina counter-clockwise direction into the position illustrated in Fig. 16.When the valve member I68 is shifted into a reverse position, that is,its extreme righthand end position, fluid under pressure passing throughthe pipe I86 passes through the valve chamber I81 and through the pipeI53 into the cylinder chamber I52 to move the piston I46 toward the left(Figs. 7 and 16) thereby moving the stop block I48 to an inoperativeposition.

The control valve I62 comprises a slidably mounted valve member I80which is controlled by a slidably mounted pilot valve member I8I. Thepilot valve member is shown in an extreme left-hand end position and isarranged to be actuated by means of the solenoids S3 and S2.

In the position of the valve I92 (Fig. 16) fluid under pressure from thepipe I64 passes through a chamber in the pilot valve member I8 I,through a passage I82 into an endchamber I83 to move the valve memberI89 into a right-hand end position as illustrated in Fig. 16. Duringthis movement of the valve member I89 fluid within an end chamber I84may exhaust through a passage I85 and out through an exhaust pipe I18.When the valve member I80 is in a right-hand end position fluid underpressure in the pipe I64 passes through a valve chamber I88! and throughthe pipe I86 to admit fluid to the valve chamber I8? in the centralvalve I6 I.

When the solenoid S2 is energized, the pilot valve member I8I is shiftedtoward the right so that fluid under pressure from the pipe I68 passesthrough the passage I85 to shift the valve member I88 toward the left sothat fluid under pressure from the pipe I64 passes through the valvechamber I86a and through the pipe I09 into the cylinder chamber 588 tocause an upward movement of the piston 99 thereby imparting a clockwiseswivelling movement to the swivel table I4.

To facilitate automatically controlling the valves I60, IEiI and I62, aplurality of limit switches actuated by adjustable dogs on the frontedge of the table are provided; .An adjustable table dog I98 is providedfor actuating a vertically movable plunger I9I against the compressionof a spring I92. A downward movement of the plunger I9I caused by dogI99 serves to close the normally open limit switches LS9 and LSIIl. Anormally open limit switch I95 is arranged to be actuated by a pair ofadjustable dogs I96 and I9! when the table is moved toward the right. Anormally open limit switch I98 is arranged to be closed by an adjustabledog I99 when the table II is moved toward the right. Similarly anormally open limit switch 208 is arranged to be actuated by anadjustable table dog I when the table II is moved toward the right. Inthe operation of the arrangement shown in Fig. 16, the swivel table I4is swivelled after each pair of cams have been ground so that surfacestapering in the opposite direction are produced on adjacent pairs ofcams. The table dogs I96, I91, I99 and 20I'are arranged so that duringthe movement of the table II toward the left, the dogs ride idly overthe respective limit switches. 'As shown in Fig. 16, the table is shownin a start position, that is, with the table in a left-hand endposition. When a grinding cycle is started, the table II indexes towardthe right to position cam No. I on the camshaft in an operative positionrelative to the grinding wheel 23. After the first two cams on theright-hand end of the camshaft have been ground and the table starts thenext indexing movement toward the right, the dog I91 engages and closesthe limit switch I95 to energize the solenoid S2 thereby shifting thepilot valve member I8I toward the right so that fluid under pressurefrom the pipe I84 passes through the passage I into the end chamber I84to shift the valve member I88 toward the left. In this position of thevalve member I80, fluid under pressure passing through the pipe I64passes through the valve chamber I86a and through the pipe I99 into thecylinder chamber I88 to move the piston 99 upwardly (Fig. 16) to swingthe swivel table I4 in a clockwise direction to position the camshaft 35for grinding cams No. 3 and No. 4 so that the surfaces will taper towardthe left. After the third and fourth cams have been ground and the tablestarts its indexing movement toward the right, the dog I99 engages andcloses the limit switch I98 which serves to energize the solenoid S3 toshift the pilot valve member I8I toward the left into the positionillustrated in Fig. 16. In this position of the pilot valve member I8I,fluid under pressure from the pipe I64 passes through the passage I82into the end chamber I83 to shift the valve member I88 toward the rightso that fluid under pressure passing through the pipe I64 may passthrough the pipe I86 into the valve chamber I81 of the valve NH andthrough the pipe I08 into the cylinder chamber I09 to cause a downwardmovement of the piston 99 (Fig. 16) to again swivel the swivel table-I4in a counter-clockwise direction to position the camshaft 35 forgrinding cams No. 5 and No. 6 on the camshaft 35 with surfaces taperingtoward the right.

During the next indexing movement of the table toward the right, the dogI96 engages and closes the limit switch I so as to again energize thesolenoid S2 thereby shifting the valve member I88 toward the left and ina manner above described causing fluid under pressure to pass into thecylinder chamber I08 to cause an upward movement of the piston 99thereby swivelling the swivel table I4 in a clockwise direction toposition the camshaft 35 in position for grinding cams No. I and No. 8on the camshaft 35 with surfaces tapering toward the left.

After the cam No. 8 has been ground, the table moves through an idlestroke toward the left. As the grinding wheel 23 approaches the truingtool I40, the dog I98 engages and depresses the plunger I9I to close thelimit switches LS9 and LSI 8. The closing of the limit switch LS9 servesto energize the solenoid SI to shift the valve member I63 so that fluidunder pressure from the pipe I64 passes through a chamber in the valvemember I63, through the pipe I58 into the cylinder chamber I5I to causethe piston I46 to move toward the right (Figs/'7 and 16) to position thestop block I48 in an operative position between the lug H6 and stopscrew I49. At the same time the closing of the limit switch LSI8energizes the solenoid S3 to shift the valve member I88 into aright-hand end position (Fig. 16) so that fluid under pressure will bepassed through the pipe I88 into the valve chamber I81 of the valve I6Iand through the pipe I86 into the cylinder chamber I81 to cause adownward movement of the piston 99 to swivel the swivel table I4 in acounter-clockwise direction. The swivelling movement of the table in acounterclockwise direction continues until the stop screw aceas'ee I49engages the stop block I48 thereby locating the swivel table in acentral position for a grinding wheel truing operation. Continuedmovement of the table II toward the left passes the truing tool I40across the face of the grinding wheel. During this movement, the dog 20Irides idly over the limit switch 200. After the truing tool hascompleted one pass across the grinding wheel 23, the table II isautomatically reversed and starts its movement in the reverse directionto again traverse the truing tool I40 across the operative face of thegrinding wheel. After the second pass of the truing tool I40 across theface of the wheel 23, the dog 20I momentarily closes the limit switch200 to momentarily energize the solenoid S4 which shifts the pilot valveI toward the left (Fig. 16) to pass fluid through the passage I'Ifi intothe end chamber I to shift the valve member I68 toward the right so thatfluid under pressure passing through the pipe I86 passes through thevalve chamber I8? and through the pipe I53 into the cylinder chamber I52to move the piston I40 toward the left thereby withdrawing the stopblock M8 to an inoperative position.

The valve member I58 remains in the righthand end position onlymomentarily. As soon as the solenoid S4 is deenergized, the releasedcompression of the spring I'II shifts the valve member I10 into theposition illustrated in Fig. 16 to shift the Valve member I63 into itslefthand end position (Fig. 16) so that fluid under pressure in the pipeI86 passes through the chamber I81, through the pipe I05 into thecylinder chamber IN to continue the downward movement of the piston 99thereby completing the swivelling movement of the swivel table I4 in acounter-clockwise directionso that the swivel table I4 is positionedcorrectly for'grinding cams Nos. I and 2 on the next camshaft 35. Thetraversing movement of the table II stops at the end of the cycle in theposition as illustrated in Fig. 16. The ground camshaft 35 may then beremoved from the machine and a new camshaft inserted therein after whichthe cycle of operation can again be carried out in a manner abovedescribed. 7

The operation of the positioning and feeding movements is coordinated asfollows: fluid under pressure is passed through a pipe 205, through athrottle valve 206, into a cylinder chamber 201 to cause the piston 46to move toward the left (Figs. 5 and 17) to cause a rapid approachingmovement of the slide I5. During th rapid approaching movement of theslide, fluid within a cylinder chamber 208 may exhaust through a pipe209, through a control valve 2) and exhaust through a pipe 2II. At thesame time fluid under pressure passes through the pipe 205, it passesalso through a throttle valve 2I2 into a cylinder chamber 2I3 to causethe piston TI to move toward the right thereby imparting a rotary motionthrough the gear 14 to rotate the feed screw I0 to impart a feedingmovement to the wheel slide base I9 and the grinding wheel slide I6.This latter feeding movement serves as a grinding feed to advance thegrinding wheel 23 into the cam being ground during the grindingoperation. During the infeeding movement caused by the piston 'I'I,fluid within a cylinder chamber 2I4 to cause a rapid movement of thepiston 'Il toward the left thereby returning the wheel slide base I9 'toits initial position. At the same time fluid under pressure also passesthrough a check valve 2I8 into the cylinder chamber 208 to cause a rapidmovement of the piston 45 toward the right to return the wheel slide IEto a rearward or inoperative position. It will be readily apparent fromthe foregoing disclosure that the throttle valves 205, M0, 2I2, and H6serve to control the speed of movement of the pistons 40 and TI.

The operation of this improved cam grinding apparatus will be readilyapparent from the foregoing disclosure. Assume the valve I 54 to beclosed to lock the piston I46 in a left-hand end position (Fig. 16) thatis with the stop block I48 in an inoperative position. The swivel tableI4 is swivelled in a counter-clockwise direction to position the camsNo. I and No. 2 on the shaft 35 in position relative to the grindingwheel 23. The table is successively indexed longitudinally toward theright to first grind No. I and then No. 2 cam. When the table indexesfor the No. 3 cam, the dog I9! actuates the limit switch I95 to energizethe solenoid S2 thereby shifting the valve member I in the control valveI62 into a left-hand end position so that fluid under pressure is passedthrough the pipe I09 into the cylinder chamber I08 to move the piston99- upwardly (Fig. 16) thereby swinging the swivel table I4 in aclockwise direction to position cams No. 3 and No. 4 in proper positionrelative to the grinding wheel 23 so that the grinding wheel 23 has anopposite taper thereon. When the table is indexed to position cam No. 5in operative relation with the grinding wheel 23, the table dog I99actuates the limit switch I to energize the solenoid S3 thereby shiftingthe valve member I80 of the control valve I02 into the position 11-lustrated in Fig. 16 so that fluid under pressure passing through thepipe I 64 enters the valve chamber I86a, passes through the pipe I80into the valve chamber I81 in the control valve IBI and through the pipeI06 into the cylinder chamber I01 so as to cause a downward movement ofthe piston 99 to swing the swivel table I4 in a counter-clockwisedirection into the position illustrated in Fig. 16 to position cams No.5 and No. 6 relative to the grinding wheel 23 so that the peripheralsurfaces thereof taper in a direction toward the right. When the tableindexes to position cam No. I in operative relation with the grindingwheel 23, the dog I96 again actuates the limit switch I to energize thesolenoid S2 thereby shifting the valve member I80 in the control valveI62 into a left-hand end position so that fluid under pressure causes anupward movement of the piston 99 to swing the swivel table I4 in aclockwise direction so that the cams Nos. I and. 8 will be ground with aperipheral surface tapering toward the left. After cam No. 8 has beenground, the table I I traverses through an idle stroke toward the leftand'returns to its initial position.

If a truing operation is desired after a camshaft has been ground, atruing operation'may be initiated when the table reaches or approachesits left-hand end position. If a wheel guard truing device is employedthen the grinding wheel may be trued at any time during the cycle and ifdesired the truing operation may be performed automatically. If desiredthe truing. tool I40 may be fixedly mounted on the table II, in whichcondition the grinding wheel may be'automatitherein specified of essaryto return the swivel table to a central position unless desired.

The apparatus as illustrated in the drawings is set up so that alternatepairs of cams on a camshaft will be ground with peripheral surfacestapering in opposite directions and a camshaft having eight cams thereonhas been illustrated. If desired the apparatus may be set up so thatalternate cams will be ground tapering in opposite directions by addingadditional table dogs for controlling the limit switches I95 and I98. Ifdesired all of the cams on one end of the camshaft may be groundtapering in one direction while the cams on the other end of thecamshaft may be ground tapering in the opposite direction byrearrangement of the dogs on the table ll.

It will thus be seen that there has been provided by this inventionapparatus in which the 'various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiments above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In a cam grinding machinehaving a base, a transversely movable wheelhead, a rotatable grinding wheel thereon, means to feed said headtransversely, a longitudinally movable table, a swivel table thereon, arotatable camshaft support thereon, means including a motor forintermittently indexing the table longitudinally successively toposition a plurality of spaced cams to be ground in operative relationto the grinding wheel, means including. an independent motor to swivelsaid swivel table in either direction, adjustable stops to limit theswivelling movement of the table in either direction, and means actuatedby and in timed relation with the longitudinal table movement to controlthe swivelling means so as to alternately swivel said table in oppositedirections after each pair of cams has been grounds to facilitategrinding a predetermined taper in opposite directions on alternate pairsof cams to be ground. I

2. In a grinding machine, as claimed in claim 1, in combination with theparts and features therein specified of means to compensate for theswivelling of the swivel table including an indexable member having aplurality of spaced adjustable stops successively to limit theapproaching movement of the wheel slide, and means including adjustabledogs on said table to index said member to shift the stop correspondingto the cam being ground into an operative position.

3. In a grinding machine, as claimed in claim 1, in combination with theparts and features means for automatically varying the operativeposition of the wheel head so as to compensate for the swivelling of theswivel table including a rotatable indexable plate, a plurality ofspaced stops on said plate to correspond with the spaced portions on theworkpiece to be ground, means including a star wheel to retate saidplate, and means including a plurality of adjustable dogs on said tableintermittently to actuate said star wheel to index said plateautomatically to position the stop corresponding to the cam being groundinto an operative position to determine the forward operative positionof the wheel head.

4. In a cam grinding machine having a base, a transversely movable wheelhead, a rotatable grinding wheel thereon, means to feed said headtransversely, a longitudinally movable worktable, a swivel table thereonhaving a rotatable camshaft support thereon, means including a motor forintermittently indexing the table longitudinally successively toposition a plurality of spaced cams to be ground in operative relationwith the grinding wheel, means including an independent motor to swivelsaid swivel table in either direction, adjustable stops to limit theswivelling movement of the swivel table in either direction, and meansautomatically actuated by and in timed relation with the longitudinalmovement of the table to control the swivel means so as to swivel theswivel table in one direction to facilitate grinding a predeterminedtaper in one direction on a portion of the cams to be ground and toswivel said swivel table in the opposite direction to facilitategrinding a, predetermined taper in the opposite direction on theremainder of the cams to be ground.

5. In a grinding machine having a base, a transversely movable wheelhead having a rotatable grinding wheel thereon, a longitudinally movabletable, a swivel table thereon having a rotatable work support thereon,means for moving the table longitudinally to position a Workpiecerelative to the grinding wheel, means to swivel said swivel table ineither direction to facilitate grinding tapers in opposite directions onspaced portions of the workpiece, means including an index pawl tofacilitate locating the swivel table in a central position for a truingoperation, and means actuated by and in timed relation with thelongitudinal movement of the table to control the movement of said pawl.

6. In a grinding machine having a transversely 'movable Wheel head, arotatable grinding wheel table movement to control the swivel motor soas to swivel said swivel table in one direction to facilitate grinding apredetermined taper in one direction on part of the portions to beground, and to swivel said swivel table'in the opposite direction tofacilitate grinding a predetermined taper in the opposite direction onthe remainder of the portions to be ground,

'7. In a cam grinding machine having a base, a

transversely movable wheel head, a rotatable grinding wheel thereon,means to feed said head transversely, a longitudinally movable table, aswivel table thereon having a rotatable camshaft support, means formoving the table longitudinally successively to position spaced cams inoperative relation to the grindingwheel, a piston and cylinder to swivelsaid swivel table in either direction, adjustable stops to limit theswivelling movement of the swivel table in either direction, and meansincluding a control valve mechanism actuated by and in tiined relationwith the table movement to control the piston and cylinder so as toalternately swivel said swivel table in opposite directions after eachcam has been ground to facilitate grinding a predetermined taper inopposite directions on alternate cams to be ground.

8. In a cam grinding machine having a base, a transversely movable wheelhead, a rotatable grinding wheel thereon, a means to feed said headtransversely, a longitudinally movable table, a

swivel table thereon having a rotatable camshaft support, means formoving the table longitudinally successively to position spaced cams inoperative relation to the grinding wheel, a piston and cylinder toswivel said swivel table in either direction, adjustable stops to limitthe swivelling movement of the swivel table in either direction, andmeans including a control valve mechanism actuated by and in timedrelation with the table movement to control the piston and cylinder soas to alternately swivel said swivel table in opposite directions aftereach pair of cams has been ground to facilitate grinding a predeterminedtaper in opposite directions on alternate pairs of cams to be ground.

9. In a cam grinding machine having a base, a transversely movable wheelhead, a rotatable grinding wheel thereon, means to feed said headtransversely, a longitudinally movable worktable, a swivel table thereonhaving a rotatable camshaft support thereon, means for moving the 2table longitudinally successively to position successive cams inoperative relation with the grinding wheel, a fluid motor to swivel saidswivel table in either direction, adjustable stops to limit theswivelling movement of the swivel table in either direction, and meansincluding a control valve mechanism automatically actuated by and intimed relation with the longitudinal movement of the table to controlthe swivel motor so as to swivel the swivel table in one direction tofacilitate grinding a predetermined taper .in one direction on a portionof the cams to be ground and to swivel said swivel table in the oppositedirection to facilitate grinding a predetermined taper in the oppositedirection on the remainder of the and means including a piston andcylinder actu ated by and in timed relation with the longitudinalmovement of the table to control the movement of said pawl.

11. In a grinding machine having a base, a transversely movable wheelhead, .a rotatable grinding wheel thereon, means to feed said headtransversely, a longitudinally movable worktable. a swivel table thereonhaving a rotatable work support thereon, means for moving the tablelongitudinally successively to position spaced portions on a workpiecerelative to the grinding wheel, a fluid motor to swivel said swiveltable in either direction, adjustable stops to limit the swivellingmovement of the swivel table in either direction, means including asolenoid-actuated control valve for controlling said swivel motor, aplurality of table dogs adjustably mounted on said table, and meansincluding a switch actuated thereby for controlling said valveautomatically to swivel .said swivel table in timed relation with thetable movement.

12. In a grinding machine having a base, a transversely movable wheelhead, a rotatable grinding wheel thereon, means to feed said headtransversely, a longitudinally movable worktable, a swivel table thereonhaving a rotatable work support thereon, means for moving the tablelongitudinally successively to position spaced por tions on a workpiecerelative to the grinding wheel, a fluid motor to swivel said swiveltable in either direction for a taper grinding operation, adjustablestops to limit the swivelling movement of the swivel table in eitherdirection, means including a solenoid-actuated control valve forcontrolling the fluid motor, means including an index pawl to facilitatelocating the swivel table in a central position for a truing operation,a fluid motor to actuate said pawl, means including a solenoid-actuatedcontrol valve therefor, a plurality of adjustable dogs on said table,and a plurality of limit switches actuated by said dogs to actuate thecontrol valves in timed relation with the longitudinal movement of saidtable.

13. In a cam grinding machine having a base, a transversely movablewheel head, a rotatable grinding wheel thereon, means to feed said headtransversely, a longitudinally movable table on said base, a swiveltable thereon, a rock bar pivotally supported on said swivel table, arotatable camshaft support on said rock bar, means including a pluralityof master cams and a follower roller in engagement therewith interposedbetween the rotatable work support and the table to impart a rockingmovement to said bar to facilitate grinding predetermined contours on aplurality of spaced cams on a cam shaft to be ground, means including amotor for indexing said table longitudinally successively to position aplurality of spaced cams to be ground in operative position relative tothe grinding wheel, and means including an indepedent motor to swivelsaid swivel table in either direction, adjustable stops to limit theswivelling movement of the table in either direction and means actuatedby and in timed relation with the longitudinal movement of the table tocontrol the swiveling motor so as to alternately swivel said table inopposite directions after each pair of cams has been ground tofacilitate grinding a predetermined taper in opposite directions onalternate pairs of cams tobe ground.

CLARENCE J. GREEN.

References Cited in the file of'this patent UNITED STATES PATENTS NumberName Date 1,693,723 Mitchell Dec. 4, 1928 1,845,172 Morey et al. Feb.16, 1932 1,970,000 Dunbar et a1 Aug. 14, 1934 2,041,244 Green May 19,1936 2,244,643 Flygare June 3,1941 2,356,394 Garside Aug. 22, 1944

